This SBIR Phase I project proposes a novel all-fiber ultra-compact high-power mode-locked fiber laser OPO system based on PolarOnyx's proprietary technologies for polarization and pulse shaping. The proposed laser system is an enabling technology for optical Coherent Anti-Stokes Raman Scattering (CARS) microscopy with two synchronized picosecond (ps) pulses. The design proposed by PolarOnyx employs photonic crystal fibers (PCFs) to manipulate dispersion, Self phase modulation (SPM), and wavelength-dependent gain. The system has no moving parts and requires very little space: the cost and size will be at least four-fold less than other competing approaches. The design is simple yet robust in construction and easy to operate. In the Phase I time frame, a prototype will be built to demonstrate mode locking and high power amplification of ps pulses and conduct a feasibility study for the design of the OPO system. In Phase II, fine tuning of the prototype to achieve high power (>200 mW average power) tunable output pulses will be performed in addition to concurrent evaluation and application of the source to CARS microscopy biophysical imaging and chemical characterization projects. [unreadable] [unreadable] [unreadable]